In this episode of TechCentral, Duncan McLeod chats via Skype to Gerrit Smit, fund manager at London-based wealth management company Stonehage Fleming, which invests billions of dollars on behalf of ultra-high-net-worth individuals. Thirty percent of Stonehage Fleming's GBI Fund is made up of investments in the technology space, with big investments including Visa, PayPal, Tencent and Accenture. In the podcast, Smit explains why he believes there's still plenty of upside for some of the world's biggest tech stocks, despite the strong rally they've enjoyed in recent years. What is the best way of determining whether these shares are good investments or not? Smit explains why he focuses on the top line and on free cash flow, in particular. Listen to the podcast to hear Smit's views on tech giants such as Tencent, Naspers, Microsoft, Apple, Amazon and Tesla.